Inspection device for inspecting foreign matter

ABSTRACT

An apparatus for transporting containers includes transport elements for transporting the containers in a transport direction, each of the transport elements including a clamping element, which is either a centering or holding element, for clamping a particular container, and an inspection device to inspect a container-to-be-inspected for unwanted foreign matter. The inspection device has a piezo sensor and is integral to the transport, centering, or holding element. The apparatus also includes an analysis unit connected to the inspection device, and an excitation element for controlling movement of a container. The inspection device is connectable to the container such that the container can be moved in an appropriate direction of movement and in the transport direction using the inspection device.

The invention relates to a container handling installation in which containers such as bottles and similar, and also cans, are transported in a transport direction by means of transport elements, said transport elements having centring and/or holding elements for clamping the particular container, wherein the container handling installation has at least one inspection device for checking bottles or similar containers, and also cans, for unwanted foreign matter, said inspection device being connected to an analysis unit.

Bottles of this kind or similar containers can be used for liquids, for example for drinks. The containers can be made of a transparent or translucent material, for example glass or a translucent plastic, e.g. PET.

The examination of such containers by means of an inspection device for unwanted foreign matter in the product filled into them is known, and occurs not only for reasons of the health of the consumer, but in the event that said foreign matter is present, can also ruin the reputation of the particular product manufacturer. This foreign matter inspection is thus carried out very thoroughly in order to prevent, for example, possible product liability claims.

These foreign matter inspections can be carried out by means of optical inspection installations such as those disclosed in DE 102 57 238 A1 or those on the basis of X-rays (for example DE 202 17 559 U1; DE 10 2006 048 327 A1; DE 202 18 138 U1).

These, in theory, well-functioning systems have their limitations where the containers to be inspected are very dark or are opaque, such as for example metal cans, or where the product is very cloudy and/or contains solids or fibres.

Also known is an inspection method in which, under laboratory conditions, a piezo sensor is used, such as the AiF short report on the 264 ZBG (new kind of multi-contact detection as the basis of an innovative hybrid system for the automatic detection of particulate solid foreign bodies in filled, flowable, non-lumpy food taking the example of products with a selected rheological constitution; Delgado, Antonio; Benning, Rainer; Forstner, Judith; Erlangen; FAU Erlangen-Nürnberg. 2009 (AIF264ZBG)).

The procedure disclosed in AIF264ZBG is reportedly suitable for recognising foreign bodies in liquids by means of a signal detection by the piezo sensor and vibration analysis following excitation of the liquid. As containers, 0.5-litre bottles were used for the investigations conducted, as used for beer or alcohol-free drinks. For the numerical simulations by means of the finite elements method (ANSYS CFX simulation software), a bottle filled with water was selected by way of example, to investigate whether a translational or a rotational acceleration should prove to be more suitable. As foreign bodies, largely spherical glass particles measuring 0.5 mm, 1.0 mm and 1.5 mm in diameter were observed. In addition, initial theoretical investigations with PET particles but also with olive oil were carried out. Due to the adjustability of the top bottle centring and the flexible bearing of the base part, the clamping force can be set at a defined level. The latter also effects a comparatively simple implementation of the necessary uncoupling from vibrations acting from the outside. The signal pick-up or detection by the piezo sensor occurs here exclusively via the base of the bottle wherein the piezo sensor is in fact stuck directly onto the base of the bottle.

Fundamentally, thus, foreign matter could also be detected in containers and/or products which are optically difficult to inspect. However, the information in the short report is based solely on laboratory measurements.

The purpose of the invention is to improve a container handling installation of the kind stated earlier or its inspection device with simple means such that unwanted foreign matter can be detected more reliably.

According to the invention, the task is solved by a container handling installation with the characteristics of claim 1, wherein the inspection device is an integral component of the transport element and/or its centring and/or holding element and is embodied as a piezo sensor, and that an excitation element is provided, which induces the container to be inspected to move in the appropriate direction of movement and halts it and/or reverses it, wherein the inspection device can be connected to the container such that it can be moved in the appropriate direction of movement and in the transport direction together with the inspection device.

By means of the invention, a container handling installation and an inspection device is provided which can reliably detect foreign matter inside the container, or within the product filled into a container. To do so, the container is clamped, for example between the centring and holding elements. By means of the excitation element, the container is then induced to make a movement which can be abruptly halted or also reversed. Due to the inertia of the product filled into the container, it rotates in the originally initiated direction of movement, whereby any foreign matter strikes the inner wall of the containers, whereby this signal is picked up or detected by the piezo sensor. Naturally, signals of contiguous wanted solids are also picked up and passed on.

The signal is fed to the analysis unit, which verifies the actual signal supplied if applicable as unwanted foreign matter, i.e. it distinguishes whether a wanted solid or unwanted foreign matter is inside the container so that the corresponding container can be removed at a subsequent station or can remain on the production line. This is not considered further.

An expedient factor in the invention is to make the piezo sensor as an integral component of the transport element and/or its centring and/or holding element, so that the inspection device is disposed on the container handling installation itself, and the container to be inspected can be connected to the inspection device briefly for the duration of the transport such that it can be released if wanted, without a piezo sensor having to be firmly bonded to the container.

A centring element in the meaning of the invention can for example be a bell which holds the container upright.

It is favourable for the inspection installation or the at least one piezo sensor to be an integral component of one such bell of the container handling installation. It is possible to arrange the piezo sensor on a bearing area of the bell for the container. It is also feasible for the piezo sensor to be arranged in such a way on the bell that it is in contact with a seal mounted on it, for example a crown cork or a screw top. In a preferred embodiment, the piezo sensor is in contact with an external wall section of the container to be inspected.

In a further favourable embodiment, the bell can have a conical basic body (cover), the top of which connects to a cylindrical, in particular a hollow cylindrical section. At the bottom, the conical basic body has at least one bearing element in which the at least one piezo sensor is disposed. The carrier element is here in a preferred embodiment basically L-shaped with a main bar and a bottom bar connected to it, wherein the carrier element is brought to rest preferably by its main bar on the outside of the container almost by spring action. The main bar can thus also be described as a spring bar. In a preferred embodiment, a number of carrier elements are disposed on the conical basic body and are preferably evenly spaced around the circumference. In a further preferred embodiment, the piezo sensor is arranged in the main bar so that a force-fitted and/or frictionally engaged contact of the piezo sensor to the container can be ensured.

On the centring element or on the bell, a slip ring assembly can also be provided for the wired transmission of power and data to and from the piezo sensor. As an energy supply however an internal energy source can also be used, which can be arranged on the centring element or on the bell.

In addition, for data transmission, a transmitter can be provided which allows wireless transmission to a receiver.

In a first embodiment, the carrier element or elements can be made such that the particular piezo sensor can come to rest in the area of the opening or in the top area of the container to be inspected. The carrier elements can however have a reach such that the piezo sensor or sensors can be brought to rest on a belly area or between the bottom and the top of the container. It is also feasible for carrier elements with different reaches to be provided so that one of the piezo sensors could be arranged on the top, another in the area of the bottom and yet another between the two. Here, various embodiments are possible.

However, it is expedient for the at least one piezo sensor always to be in contact with the container to be inspected, regardless of which direction of movement and/or transport direction the latter carries out.

As the excitation element can induce the container to move not only around its vertical axis but also along it, or at an angle to it, and abruptly halt or even reverse this movement generated in each case. Thus unwanted foreign matter but also a wanted solid can be induced to hit against the internal wall or come into contact with it, and this can be measured or picked up and passed on by means of the piezo sensor or sensors as a signal, deflection or peak.

By means of the bell and the plate, the container is thus clamped in its vertical axis. In a preferred embodiment, the excitation element can be arranged directly on a plate, on which the container is held upright in the transport direction.

The excitation element can be in the form of a rotary drive which induces the container to make a rotational movement around its vertical axis. The excitation element can be in the form of an autonomous drive, or however as a rotary drive of known rotary plates.

It is expedient for one or more piezo sensors to be arranged on the plate or to be an integral component of it.

In addition, one embodiment which is similar to the bell described can advantageously be expedient. In other words, carrier elements can be provided which extend away from the standing space of the plate, and the main bars of which, supporting the piezo sensors, are in spring-like contact with the outer wall of the container. Naturally, here, in particular the areas of the main bars which have the piezo sensors should be in contact with the container, and this should apply correspondingly for the bell. Of course, the carrier elements can have a different or the same longitudinal reach.

In a further embodiment, the carrier elements can be arranged not only rigidly on the bell or the carrier or other suitable locations, but also can be moved from a rest position into an inspection position and back. For this, suitable drives, for example electromotive or pneumatic drives can be provided which move the carrier elements along the vertical axis of the container to be examined. Here, the carrier element with its measuring area, i.e. with the area in which the piezo sensor is arranged, can be moved from below against the base of the container, or be moved past the base and placed on a belly area of the container, and this thus naturally applies similarly for moveable carrier elements on the bell too. The energy supply to drive the rotary drive, the carrier element and/or for the piezo sensor can be integrated in the plate or be external. Also, a wired or wireless signal transmission from at least one piezo sensor to the analysis unit is possible.

However, it is also feasible for the at least one piezo sensor to be integrated in the plate itself. To this end, the plate can have at least one carrier layer and one sensor layer, i.e. can be structured with at least two layers. It is thus possible for the bottle carrier layer to be arranged radially on the outer part, and the sensor layer to be provided inside, i.e. centrally. Carrier materials can be metal, glass, ceramic, gel, gel pads, liquids of a suitable kind and/or technical fabric. A multi-layer structure is of course possible too. It is also feasible for the piezo sensor or sensors to be cast in the plate or in its metal baseplate. Crucial here however is also that the piezo sensor or sensors are in contact with the container surface so as to be able to pick up the impact signal.

The container handling installation can be a filling machine, labelling machine, sealer or an independent inspection installation which has other inspection tasks. A design with a circumferential conveyance or a linear conveyance of the containers is also feasible. With a circumferential conveyance, the inspection device can be arranged on an inlet star, a production or main star, or the outlet star. The energy supply to the piezo sensor or sensors can be by means of one of the stars.

As already mentioned, it is also feasible that a linear machine or a linear transporter which includes at least an endlessly circulating transport element, which can be in the form of a conveyor belt, wherein the at least one piezo sensor is arranged in the conveyor belt corresponding to the container position. Thus, the piezo sensor is in contact with the container in the linear transporter. Of course, the linear machine can also have a bell and a plate, between which the container can be clamped so that here too the aforesaid embodiments are possible.

To this extent, by means of the invention, a method for inspecting containers with an inspection device in one of the previously described embodiments is provided, wherein the method includes at least the following steps:

-   -   holding the container in the transport direction,     -   bringing the at least one piezo sensor into contact with the         container, wherein the piezo sensor is an integral component of         the transport element and/or is its centring and/or holding         element,     -   inducing the container to move,     -   halting or reversing the induced movement,     -   picking up or detecting signals from particles impacting on the         inner wall of the container by means of the at least one piezo         sensor, and     -   forwarding or transmitting the signals picked up to an analysis         unit which detects a decision with regard to containers         containing foreign matter or not containing foreign matter.

It is of course possible for individual steps to be carried out a number of times, i.e. to be carried out repeatedly on a single container. In particular, inducing the container to move and halting or reversing the movement can be repeated a number of times.

Of course, a number of data sets of a number of piezo sensors can be picked up and analysed at the same time. The direction of movement can naturally be reversed directly without the intermediate halt stage (naturally, a short, chronologically restricted halt does necessarily mechanically occur). The excitation into movement can be even, i.e. constant, whereby a pulse-type inducing is also feasible. It is also possible, as already stated, to overlap the vertical and horizontal direction of movement, i.e. a quasi vibration excitation of the container to be inspected.

The analysis unit can combine amplifier, computer, converter and/or filter elements, and be embodied also almost as a control unit. As part of the signal forwarding, on the data path from the piezo sensor to the analysis unit, one or more signal amplifications and signal filters are provided. In a particularly preferred solution, the signal picked up by the piezo sensor without a signal filter is passed on to the analysis unit and the complete data processing and analysis takes place in the analysis unit.

Further advantageous embodiments of the invention are disclosed in the subsidiary claims and the following illustrations. The following are shown:

FIG. 1 a container handling installation in a perspective partial view

FIG. 2 a centring element as an individual unit,

FIG. 3 a holding element as an individual unit, and

FIG. 4 a container by way of example with measuring areas shown by way of example.

In the various figures, the same parts are always given the same reference symbols, and hence they are generally also only described once.

FIG. 1 shows a container handling installation 1 in an embodiment by way of example as a labelling machine or labelling carousel. The container handling installation 1 has a number of transport elements 2 which each have a centring and holding device, i.e. each a standing area 3 and each a bell 4.

The standing area 3 is made in the known way as a rotary plate 3, wherein the bell 4 is mounted on a drive device 5 such that it can be raised and/or rotated. With the centring and holding devices 3, 4, containers 7, for example PET bottles, are rotated around the central axis X of the container handling device 1, and fed for example to labelling units. In this way, the bases of the containers 7 stand on the particular rotary plate 3 and are held at the top by means of the bell 4, or are clamped between them.

Expedient in the meaning of the invention is that at least one inspection device 8 in the embodiment as a piezo sensor 8 is provided as the inspection device 8 for the internal inspection of the container 7 for unwanted foreign matter, said piezo sensor being preferably embodied as an integral component of the bell 4 (FIG. 2) and/or the rotary plate 3 (FIG. 3), i.e. as an integral component of the particular transport element 2. Naturally, other inspection devices can also be provided for example to check the label position or to orient the containers, but these however are not the subject of this invention.

By means of the bell 4 and/or the rotary plate 3, the container 7 can furthermore be induced to move in a direction of movement in addition to the transport direction. The transport direction in the meaning of the invention is the direction in which the container is supplied to the individual consecutive processing stations and/or inspection stations, wherein the direction of movement is generated independently of the transport direction. Thus, the direction of movement around the vertical axis of the container can however be generated along it or at an angle to it or even overlapping.

Preferred is that, by means of a rotary drive, a rotary movement of the container around its vertical axis is generated, for which the rotary plate 3 with its rotary drive is most suitable as it can also generate revolutions of more than 1000 rpm. In this respect, rotary plate 3 is not only a standing and orientation element but additionally has the function of an excitation element to induce the movement of the container 7. Naturally, the bell 4 can also function as the excitation element.

The inspection device 8 in the advantageous embodiment as a piezo sensor 8 is able to detect unwanted foreign matter in products in which, for example, optical methods reach their limits.

In a first embodiment, a piezo sensor 8 can be integrated on the bell 4 such that the bearing surface of the bell 4 for the container 7 is to be regarded as a measuring area in which the at least one piezo sensor 8 is arranged at least in certain areas (FIG. 4).

The bell 4 (FIG. 2) has, in a known embodiment, a conical basic body 9 (cover) which extends from a top side 10 to a bottom side 11. A cylindrical section 12 is provided on the top which can be connected to the drive device 5. In contrast to known bells, the bell 4 according to the invention has at least one carrier element 14 on its bottom face 13, wherein in FIG. 2 a number of carrier elements 14 are provided which are provided preferably distributed evenly spaced around the circumference.

The relevant carrier element 14 is basically L-shaped with a main bar 15 and a base bar 16, wherein the base bar 16 is oriented radially outwards from the main bar 15. The main bar 15 is almost formed as a spring bar so that it can lie on the outer side almost by spring action on an opening section or side wall section of the container 7.

Preferably in each main bar 15, at least one piezo sensor 8 is integrated, namely in such a way that it can come into contact with the external surface of the container 7. As can be seen in FIG. 2, all piezo sensors 8 can come into in contact with the container surface or in the top area with the external side wall.

To provide an energy supply for the at least one piezo sensor 8, by way of example a slip ring transmitter 17 is provided which solely by way of example is arranged on the top of the conical basic body 9. The slip ring transmitter 17 can also be used as the data transmitter of the piezo sensor 8 to an analysis unit 18. Energy and data lines are shown by dashed lines in FIG. 2. However, an internal energy supply to each bell 4 is possible, or a wireless data transmission, for which in FIG. 2 optionally transmitter 19 and receiver 20 are shown, said transmitter being in turn connected to the analysis unit 18.

In the example of an embodiment shown in FIG. 2, all carrier elements 14 have the same longitudinal reach. It is also possible to make the various carrier elements 14 with different longitudinal reaches. Thus, at least one piezo sensor 8 can be in contact with e.g. a belly area 21 (FIG. 4) of the container 7, wherein at least one more can be arranged in its opening area 22 (FIG. 4). It is feasible for each carrier element 14 to be made so that it can be moved in its longitudinal direction preferably individually so that almost any desired area of the container 7 can be measured with the piezo sensor 8 along the longitudinal axis of the carrier element 14. To do so, the carrier elements 14 can be moved from a rest position into an in each case freely selectable measuring or inspection position.

Similarly to the embodiment of bell 4, the rotary plate 3 too could be made with carrier elements 14 which can encompass the container base area laterally as can be easily imagined. Each carrier element 14 has here at least one piezo sensor 8 integrated in it. FIG. 3 shows an embodiment such as this wherein here the standing area of the plate 3 on which the container stands is oriented to the bottom edge of the illustration. The carrier elements 14 of the plate 3 are oriented towards the bell 4. The external energy supply not only to the carrier elements 14 but also to the piezo sensors 8 can, as in known rotary plates, be for example by means of a slip ring, an inductive conveyor (RFID) and/or by means of a dynamo supply. The same applies for the bell 4. Moreover, a data connection to the analysis unit 18 can still be provided, which is not shown in FIG. 3. It basically applies that the carrier elements 14, as described with regard to the bell 4, can similarly also be provided on the plate 3.

Likewise feasible is a moveable embodiment of the carrier element 14 on the rotary plate 3. Also possible is the provision centrally in rotary plate 3 of a preferably moveable carrier element 14 which can measure the outer surface of the base of the container. A moveable element can also be integrated in the bell 4 so as to lie on the seal in order to be able to carry out the measurement.

However, it is also feasible to integrate the piezo sensor 8 in a rotary plate 3 made with multiple layers. Here, for example one layer can be made as a carrier layer, which carries the container 7, wherein the other layer is made as a sensor layer. The carrier layer here can be arranged radially on the outer part, whereby the sensor layer can be arranged centrally. Naturally, the bell 4 can also be made on the bearing area for the container 7 with a carrier layer and a sensor layer.

The container is set in rotation for example by the excitation element. Due to the rotation, the liquid filled into it is correspondingly carried along, wherein there can additionally be impact contact of unwanted foreign matter and/or wanted solids which may be in the liquid with the inner wall of the container 7. This impact contact can now be recorded by the at least one piezo sensor 8 and supplied to the analysis unit 18. The analysis unit 18 can verify the various signals to establish whether or not a container contains unwanted foreign matter.

Feasible positions of the piezo sensors 8 on the container surface are shown in FIG. 4.

Naturally, the at least one piezo sensor can be arranged not only on the labelling machine for example, but also on filling machines, sealing machines and similar container handling installations. These container handling installations can be made with a rotating transport direction or also as a linear conveyor. In linear transporters, at least one piezo sensor 8 can be integrated in the transport element in the embodiment as a conveyor belt or be integrated in the drive axle of a conveyor belt and rotate with this drive axle.

If the container handling installation is made as a sealing machine, the at least one inspection device 8 as a piezo sensor can be an integral component of the sealing head, whereby not only contact with the outer wall of the container but also with the sealing element (e.g. crown corks, screw cap) can be expedient, whereby the at least one piezo sensor or multiplicity of piezo sensors can be oriented parallel to the sealed opening. An inspection for unwanted foreign matter can take place at the same time as the sealing, whereby the sealing can be carried out first and then the inspection. Also feasible is carrying out a cap-sit check and a leak test on the seal, in particular by means of one or more piezo sensors. Also possible is determining the quantity of product filled by means of a piezo sensor simply by carrying out a weight measurement. It is also feasible to integrate piezo sensors in grab sections and/or in plates of filling machines.

Also possible is an embodiment in which the piezo sensor measures without contact. 

1-13. (canceled)
 14. An apparatus for transporting containers, said apparatus comprising a container handling installation, said container handling installation comprising transport elements for transporting said containers in a transport direction, each of said transport elements comprising a clamping element for clamping a particular container, said clamping element being selected from the group consisting of a centering element and a holding element, an inspection device to inspect a container-to-be-inspected for unwanted foreign matter, said inspection device comprising a piezo sensor and being an integral component of a structure selected from the group consisting of said transport element, said centering element, and said holding element, an analysis unit connected to said inspection device, an excitation element configured for controlling movement of a container-to-be-inspected, wherein controlling movement of said container-to-be-inspected comprises carrying out a movement selected from the group consisting of moving said container-to-be-inspected in a particular direction, reversing movement of said container-to-be-inspected, and halting movement of said container-to-be-inspected, whereby said inspection device is connectable to said container-to-be-inspected such that said container-to-be-inspected can be moved in an appropriate direction of movement and in said transport direction using said inspection device.
 15. The apparatus of claim 14, wherein said inspection device is an integral component of an element selected from the group consisting of said centering element and said holding element of said container handling installation.
 16. The apparatus of claim 14, wherein said inspection device is connected to a side wall area of said container.
 17. The apparatus of claim 14, wherein at least one of said centering element and said holding element comprises a carrier element, said carrier element comprising said inspection device as an integral component thereof.
 18. The apparatus of claim 14, further comprising carrier elements that can be moved from a rest position into a measuring position, wherein said inspection device is integrated into one of said carrier elements.
 19. The apparatus of claim 14, wherein said excitation element is configured to induce said container-to-be-inspected to move around a vertical axis thereof.
 20. The apparatus of claim 14, wherein said excitation element is configured to induce said container-to-be-inspected to move along a vertical axis thereof.
 21. The apparatus of claim 14, wherein said excitation element is configured to induce said container-to-be-inspected to move so as to form an angle relative to a vertical axis thereof.
 22. The apparatus of claim 14, wherein said centering element comprises a bell, and wherein said holding element comprises a plate.
 23. The apparatus of claim 14, wherein said holding element comprises a sensor layer and a carrier layer.
 24. A method for internal inspection of containers in a container handling installation as recited in claim 14, said method comprising holding a container in said transport direction, bringing said piezo sensor into contact with said container, inducing said container to move, at least one of halting and reversing said induced movement, using said piezo sensor, picking up signals from particles impacting on an inner wall of said container, and forwarding a signal to an analysis unit that determines whether or not said container contains foreign matter, wherein said signal is selected from the group consisting of signals picked up and electrical data signals derived from said signals picked up.
 25. The method of claim 24, wherein forwarding said signal comprises amplifying and filtering said signal.
 26. The method of claim 24, further comprising amplifying said signal when forwarding said signal, and, at said analysis unit, filtering said signal.
 27. The method of claim 24, wherein inducing movement of said container comprises repeatedly inducing said movement.
 28. The method of claim 24, further comprising receiving data from a number of inspection devices simultaneously, and analyzing said data simultaneously. 